Combustion of fuel.



P. 0. PERKINS. COMBUSTION 0F FUEL.

APPLICATION FILED MAY 6, 1915. 1,146,732. Patented July 13, 1915.

IN I/E/V TOR.

A ITOR/VEJS COLUMBIA PLANDGRAFH co., WASHINGTON. D. C

'PEROIVAIi O. PERKINS, 0F SALT LAKE CITY, UTAH.

COMBUSTION OF FUEL.

mamas. I v

To all whom it may concern: 1

Be it known that I, PEROIVAL O. PERKINS, residing at No. 163 South State street, Salt Lake City, county of. SaltLake, State of Utah, have invented certain new and useful Improvements in the Combustion of Fuel; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, I

The present inventionlisbased upon the discovery that bythe conjoint use of two dilferent kinds of fuels, (to wit, bituminous coal, and oil-bearing shales) it is possible to obtain the practically complete consumption of the combustible constituents of each, with substantial avoidance of'smolre in the ultimate products of combustion delivered to the outer air and with the production of a fine brittle ash practically devoid of clinkers and therefore having. no tendency to clog the grate upon which the composite fuel is being burned.

The invention is particularly adapted for use, in localities wherein the main source of available fuel is bituminous coal, whose consumption, under ordinary conditions, is accompanied with the giving off of dense clouds of smoke, due largely to the voluminous distillation of hydrocarbons having a high carbon content from the coal, andthe difficulty experienced in effecting the combustion of these hydrocarbons on their way to the furnace stack or chimney. I 1

As will hereinafter more fully appear, the

present invention realizes the necessary conditions for burning bituminous coal with the smokeless consumption of its combustible elements. At the same time, the invention makes available for commercial use as a fuel, the large deposits of oil-burning shales, which are frequently found in regions where bituminous coal is likewise available.

Oil-bearing shales have heretofore found their principal utilization in the distillation therefrom of the heavy petroleum oils which they contain, the uncondensable gases developed during the distillation being ordinarily employed for heating the distillation retorts. On the other hand, the employment of oil-bearing shales directly as fuel has encountered the difficulty that, although the oil burns freely and rapidly, the high ash content of the shale (ranging usually from 75-85%) gives a residuum which clogs the Patented July 13, 1915.

Application filed May 6, 1915. Serial No. 26,222.

grate. The conjoint use of the two fuels,

associated in suitable proportions enables the one to correct the disadvantages of the other and provides a composite fuel which not only utilizes to advantage products which are relatively inexpensive as compared with anthracite coal, but which also can be employed as an eiiicient substitute for anthracite coal for many industrial and domestic purposes; as, for instance, for boiler firing, for metallurgical and similar heating furnaces, for gas producers, and for ordinary grates, stoves, and furnaces.

For purposes of illustration, there is shown, in the accompanying drawing, the preferred application of the invention to the heating of a steam boiler installation.

In the drawing, Figure 1 represents, in longitudinal section, a partial view of a steam boiler furnace of a well-known type, provided with a furnace grate adapted to receive and burn the charge of bituminous coal and oil-bearing shale; Fig. 2 represents, in transverse section, a fragmentary view of the grate, with its charge of fuel arranged in accordance with the preferred practice.

Similar letters of reference indicate similar parts in both views.

Referring to the drawing, A indicates a fire tube boiler, adapted to be heated by products of combustion supplied from the burning of fuel on the grate a. In furnaces of this type, it has been found that excellent resultsare obtainable by employing a grate whose top surface is 5 ft. by 7 ft. in area and whose bridge wall I) is, say, 20 inches higher than the grate, the bed of fuel being from 6 to 8 inches in depth over the entire grate surface. For general use, in furnaces of this character, therefore, these dimensions are recommended, although, as hereinbefore noted, it will be understood that the invention, broadly considered, is not confined to this particular use.

In using the invention in connection with a steam boiler furnace of the kind shown, a body of fuel is first ignited and burned upon the grate, and when the fuel has attained incandescence, it is raked or pushed back to a position near the bridge wall, as indicated at 0. Thereupon, the grate is charged with a bed of bituminous coal and oil-bearing shale. In the preferred practice, the shale is screened to one-inch mesh, and is preferably charged in a super-jacent layer d resting upon a lower layer 6 of bituminous coal, the depth of the layer of coal being preferably about twice the depth of the layer of oilbearing shale. Under these conditions, the layer of oil-bearing shale immediately takes fire from the heat of the body of incandescent coal 0 and burns with an intense flame which rapidly propagates itself over the entire surface of the fuel bed. The heatof the burning oil is thus communicated to the bituminous coal, and the heavy hydrocarbons begin to distil from the coal and pass up ward through the zone of flame issuing from the top surface of the fuel bed. Sufficient air being admitted into the ash pit, (either by forced draft or by chimney draft, or both,) practically complete combustion of the hydrocarbons given off from the coal takes place in the flame area. The combustible elements of both the bituminous coal and the oil-bearing shales are consumed in their substantial entirety, and the resultant ash is of abrittle and friable character, practically devoid of clinker.

As indicated, it is preferred to make up the fuel bed of separate layers of bituminous coal and oil-bearing shale, andof the relative depths referred to; for the reason,

among others, that it is found that by so domg the amount of oil-bearing shale required to insure the complete combustion of the bituminous coal with the resultant fine nonclinkering ash, is less than when the two kinds of fuel are mixed before charging. It

- will be understood, however, that it is not always feasible to charge the separate layers with exactness and, furthermore, itis not absolutelynecessary to do so, for thereason that results of a satisfactory character can beobtained even by mixing the bituminous coal and oil-bearing shales before charging Copies of this patent may be obtained for them upon the furnace grate or into the stove or other chamber in which they are to be consumed. It is to be understood, therefore, that the invention is not limited to the particular manner of arrangement of the two fuels illustrated in the drawing but is to be given a broad and generic interpretation commensurate with the claims hereinafter made. i

What I claim is: I

1. The method of utilizing, as fuel, bituminous coal and oil-bearing shale, which comprises associating with the bituminous coal and burning therewith a proportion of oil-bearing shale suflicient to produce smokeless combustion, and to preventclinkering in the resultant ash; substantially as described.

2. The method of utilizing, as fuel, bituminous coal and oil-bearing shale, which comprises associating Wltll'tll) bituminous coal and burning therewith upon a grate surface, a shallow fuel bed made up of bituminous coal and oil-bearing shale associated in such proportions that the resulting combustion will be smokeless and the resulting ash clinkerless;.substantially as described.

3. The method o'f,utilizing,'as fuel, bituminous coal and oil-bearing shale, which comprises associating with the bituminous coal and burning therewith upon a grate surface, a shallow fuel bed made up of bituminous coal and oil-bearing shale associated in such proportions that the resulting combustion will be smokeless and the resulting ash clinkerless, said fuel bed consisting of a' lower layer of thebi'tuminous coal and stantially as described.

- In testimony whereof Ijaffix my signature.

PERGlVAL O. PERKINS.

an upper layer of the oil-bearing shale; subfive cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

